[llvm] r252432 - [AsmParser] Allow tokens to be put back in to the token stream.

[Colin LeMahieu via llvm-commits]

Author: colinl
Date: Sun Nov  8 17:48:23 2015
New Revision: 252432

URL: http://llvm.org/viewvc/llvm-project?rev=252432&view=rev
Log:
[AsmParser] Allow tokens to be put back in to the token stream.

Differential Revision: http://reviews.llvm.org/D14252

Modified:
    llvm/trunk/include/llvm/MC/MCParser/MCAsmLexer.h
    llvm/trunk/lib/MC/MCParser/MCAsmLexer.cpp

Modified: llvm/trunk/include/llvm/MC/MCParser/MCAsmLexer.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/MC/MCParser/MCAsmLexer.h?rev=252432&r1=252431&r2=252432&view=diff
==============================================================================
--- llvm/trunk/include/llvm/MC/MCParser/MCAsmLexer.h (original)
+++ llvm/trunk/include/llvm/MC/MCParser/MCAsmLexer.h Sun Nov  8 17:48:23 2015
@@ -118,7 +118,7 @@ public:
 /// lexers.
 class MCAsmLexer {
   /// The current token, stored in the base class for faster access.
-  AsmToken CurTok;
+  SmallVector<AsmToken, 1> CurTok;
 
   /// The location and description of the current error
   SMLoc ErrLoc;
@@ -148,7 +148,15 @@ public:
   /// The lexer will continuosly return the end-of-file token once the end of
   /// the main input file has been reached.
   const AsmToken &Lex() {
-    return CurTok = LexToken();
+    assert(!CurTok.empty());
+    CurTok.erase(CurTok.begin());
+    if (CurTok.empty())
+      CurTok.emplace_back(LexToken());
+    return CurTok.front();
+  }
+
+  void UnLex(AsmToken const &Token) {
+    CurTok.insert(CurTok.begin(), Token);
   }
 
   virtual StringRef LexUntilEndOfStatement() = 0;
@@ -158,7 +166,7 @@ public:
 
   /// Get the current (last) lexed token.
   const AsmToken &getTok() const {
-    return CurTok;
+    return CurTok[0];
   }
 
   /// Look ahead at the next token to be lexed.

Modified: llvm/trunk/lib/MC/MCParser/MCAsmLexer.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/MC/MCParser/MCAsmLexer.cpp?rev=252432&r1=252431&r2=252432&view=diff
==============================================================================
--- llvm/trunk/lib/MC/MCParser/MCAsmLexer.cpp (original)
+++ llvm/trunk/lib/MC/MCParser/MCAsmLexer.cpp Sun Nov  8 17:48:23 2015
@@ -12,8 +12,8 @@
 
 using namespace llvm;
 
-MCAsmLexer::MCAsmLexer() : CurTok(AsmToken::Error, StringRef()),
-                           TokStart(nullptr), SkipSpace(true) {
+MCAsmLexer::MCAsmLexer() : TokStart(nullptr), SkipSpace(true) {
+  CurTok.emplace_back(AsmToken::Error, StringRef());
 }
 
 MCAsmLexer::~MCAsmLexer() {